Interlocking system for railroads



June 2, 193.. W. K. i-lQWE INTERLOCKING SYSTEM FOR RAILROADS Filed May 25, 1936 2. Sheets-$heei l m2 3 mv INVENTOR AToRNY June 2%, 19338. W. K. HQWE INTERLOCKING SYSTEM FOR RAILROADS Filed May 23, 1936 2 Sheets-Sheet 2 ATTORNi-IY Patented June 28, 1938 UNITED STATES PATENT OFFICE Winthrop K. Howe, Rochester, N. Y., assignor to General Railway Signal Company, Rochester,

Application May 23, 1936, Serial No. 81,419

16 Claims.

This invention relates in general to interlocking systems for railroads, and more particularly to a controlling button or lever for use in establishing routes in an interlocking system wherein the interlocking between the various traflic controlling devices is accomplished by the proper selection of electrical circuits.

The present invention however is to be considered as an improvement over the systems of entrance-exit interlocking disclosed in the prior applications of S, N. Wight Ser. No. 721,696 filed April 21, 1934 and Ser. No. 69,905 filed March 20, 1936.

In the type of interlocking system contemplated by the present invention, a miniature track layout is provided on a control panel which corresponds to the actual track layout, and controlling buttons or levers are located on the miniature track layout at points corresponding to the location of signals along the actual track. In order to establish a'route or a train movement in a particular direction over the represented track layout, the operator merely operates the controlling buttons at the two opposite ends of the desired route which serves to both effect the operation of all the track switches involved in that route to their proper positions and to thereafter cause a signal to clear allowing a train to traverse such route providing that it is safe to do so.

A means for establishing these routes has usually taken the form of two controlling buttons at each end of each route, one of these buttons being rotatable and mechanically retained in. its last operated position which may be termed the entrance or initiating button, while the other is usually a self-restoring push button which may be termed the exit or completing button. The entrance and exit buttons at one end of each route are usually separate units, and although they are associated physically by their adjacent location in the track diagram, these two buttons are actually associated with different route directions and are not operated in combination to establish any one route. In aligning a route, the operator in such an arrangement must turn the initiating button at the entrance end of the desired route and then press the completing button at the other or exit end, and after a train movement has been completed over the route, the operator must then return the initiating button to its normal position before aligning another route.

In accordance with the present invention, however, it is proposed to provide an improved means for aligning routes in an interlocking system of the above type. More specifically, it is proposed to provide a composite controlling means for each end of each route comprising an initiating button and a completing button concentric therewith, whereby to conserve space and to simplify the layout of the control panel.

It is also proposed to provide an electromagnetic means for retaining the initiating button in its operated position and for releasing or automatically restoring the initiating button to its normal position when a train accepts the route aligned thereby. In this manner the operator is not required to manually restore-the initiating button to its normal position after a route aligned thereby has been accepted by a train, and consequently is free to proceed with other operations such as the alignment of other desired routes.

However, in some instances, it may be desirable to allow a second train to follow over the same route and consequently it is undesirable to automatically cancel the route alignment when accepted by the first train. It is therefore proposed to provide an initiating button of the above type which, when operated to align a route, is magnetically retained and automatically released as stated, unless it is further operated in a distinctive manner which mechanically retains its depressed position until released by the reverse manual operation.

It is also proposed to provide an initiating button of the above type which may be distinctively operated manually to select which of a plurality of signal aspects is to be displayed over the route selected thereby. More specifically, it is proposed to provide a controlling means as stated above wherein the initiating button may either be, depressed to select the normal signal over the route selected thereby and automatically released, or mechanically retained by turning when in its depressed position, or if it is desired to select a different character of signal over the same route such as a call-on signal, the initiating button may be turned rather than depressed.

Still other objects, purposes and characteristic features of the present invention will be obvious as the description thereof progresses, during which references. will be made to the accompanying drawings, in which:

Fig. l is an enlarged sectional side elevational View of one form of a manual controlling means arranged in accordance with the present invention.

Fig. 2 is a plan view of a portion of the control means shown in Fig. 1 with the contact arrangement developed as upon a fiat surface to more clearly show the arrangement thereof.

Fig. 3 shows in a simplified and conventional manner one application of the present controlling means to an interlocking system for railroads.

Fig. 4 shows a modification which may be made in the arrangement shown in Fig. 3.

In Fig. l of the accompanying drawings, the present controlling means is illustrated as mounted on a vertical control panel 5 which may have a diagram of the associated railway track suitably marked on the face thereof in the usual manner. A terminal board or insulating panel I is also shown spaced to the rear of the control panel 5, which terminal board I is preferably permanently mounted and carries thereon suitable wire terminal means which are detachably connected to the contacts of the present controlling means, as will be later described.

The controlling means is illustrated as comprising a cylindrical case I of suitable insulating material such as moulded phenolic compound, the front portion of the case I!) being of a reduced diameter and extending through a hole in the terminal board I with the extreme front end of a further reduced diameter forming a shoulder engaging the rear surface of panel 5. A clamping nut I I is threaded on the front end of the case l0 against the front surface of panel 5, whereby case It! is jointly supported by the two panels and I in a cantilever manner.

A hollow shaft member I2 extends longitudinally through the case II), the front portion of shaft I2 being of an enlarged diameter forming a shoulder engaging the front end of a compression spring I 3, the rear end of the spring I3 ennular groove in bushing I4.

gaging a bushing I4 surrounding the smaller diameter of shaft I2 and retained within the case I0 by a transverse pin I5 resting in an outer an- The shaft I2 is thus biased by outer spring I3 to a position limited by a transverse pin I8 carried by the case I0 and passing through slots I9 in the enlarged portion of the hollow shaft I2. These slots I 9 are shaped as indicated in Fig. 2 to permit either a longitudinal rearward movement or a turning movement of the shaft I2 relative to the case Ill. The front end of shaft I2 extends beyond the end of case l0 and carries a knob NB shaped as shown in Fig. 3 and removably secured thereto by a screw 2|.

The enlarged front end portion of the hollow shaft I2 surrounds an inner push button plunger XB extending through the front end of knob as shown. The rear portion of plunger XB is hollow to enclose a compression spring 24 which engages pin IE to bias the plunger toward its outer position, which position is limited by slots 25 in the plunger 22 permitting only longitudinal motion thereof. The rear end of plunger XB is suitably attached to a shaft 28 extending rearwardly through the center of the hollow shaft I2.

The enlarged rear portion of case Ill encloses an iron-clad electromagnet comprising a winding S around a hollow magnetic core 30, which core 30 surrounds the outer shaft I2 and is attached at its rear end to a magnetic cup-shaped outer member 3! by a nut 32 threaded thereon. A disc NS of magnetic material is attached concentrically to the outer shaft I2 to comprise an armature coacting with this electromagnet. In

this manner, the magnetic disc or armature NS is moved rearwardly to a position completing the magnetic circuit around winding S when the knob NB is depressed, and with the winding S energized, the armature NS is then retained against the core 30 and the outer member 3|, to hold the outer hollow shaft I2 in its rearward or right hand position against the biasing force of spring I3. However, when winding S is deenergized, it will be clear that armature NS is released and spring I3 returns shaft I2 to its forward outer position, or it is contemplated that it will also be possible to manually restore the shaft I2 to its forward position by pulling forwardly on knob NB, even though the winding S is energized.

The rear end of the outer hollow shaft I2 extends beyond the rear end of case I0 and carries a disc 35 of insulating material mounted concentrically thereon by a nut 36. The disc 35 carries sectors or metal contact pieces, such as A shown in Fig. 1, embedded therein and cooperating with low resistance contact points of contact fingers, such as C in Fig. 1, arranged longitudinally in spaced parallel relationship around the outer surface of the enlarged rear portion of case 10.

The rear end of the inner shaft 28 extends beyond the rear end of the outer shaft I2, and carries a disc 38 of insulating material between two nuts 39 threaded thereon, which disc 38 carries a metal contact ring M cooperating with low resistance contact points of certain contact fingers, such as fingers O and P in Fig. l, which fingers are longer than the fingers such as C cooperating with disc 35, but are arranged on case II) in the same manner. The fingers such as C, O and P are retained at the front and rear ends of the enlarged portion of case II] by screws 40 threaded therein, the rear screws 40 being threaded into a ring 42 of insulating material closing the end ofcase I0, which ring 42 also serves to space the electromagnet by a nut 43 threaded on the rear end of the core member 30.

The front ends of all the contact fingers such as C, O and P in Fig. 1 extend beyond the front end of the enlarged portion of case ID to form prongs which are plug connected to stationary terminal means arranged on the terminal board I. These stationary terminal means each comprise two spring contacting strips 45 permanently attached to the front surface of panel I by a hollow rivet 46, the free end of these strips being separated and extended through holes in panel I with pressed-out contact surfaces engaging opposite sides of the extending end portion of contact fingers such as C and O. The electrical conductors such as conductor 48 which connect the present controlling means with the other apparatus of the system are permanently connected to these terminal means such as by soldering within the hollow rivets as shown.

In this manner, it will be clear that by removing nut II and knob NB, the present controlling means may be quickly and conveniently removed from the rear of its supporting panels 5 and 1 without disturbing the arrangement of electrical conductors on the terminal means of panel 1. Likewise, it will be clear that if the front panel 5 is removable, the electrical conductors such as 28 may be easily arranged on the terminal means of panel 1 before the control device is installed, thus permitting better workmanship, and permitting access to the various circuits for inspection or testing.

In Fig. 2 of the accompanying drawings, the two concentric shafts I2 and 28 are shown attached to the respective members 35 and M operated thereby, the members 35 and M being illustrated as laid out or developed on a fiat surface to show the manner in which they cooperate with the contact fingers. It may also be seen in Fig. 2 which is a plan view of portions of the device shown in Fig. 1, how the slots it are arranged in the outer shaft l2, or that is, the slots l9 receiving the stationary pin it permit the knob NB to be turned in a clockwise direction from its normal illustrated position, which may be considered to move the developed representation ofrdisc 35 longitudinally in a downward direction in Fig. 2. Likewise, it will be seen that the shaft l2 may be moved longitudinally from its illustrated position which accordingly moves the disc 35 transversely to the right.

In Fig. 2 it may be seen that the slot i9 is so shaped that when the shaft i2 is pushed longitudinally to the right, it may then be turned slightly in a clockwise direction, whereupon it is mechanically retained in this position against the action of spring l3 until it is manually turned back in a counterclockwise direction, regardless of the energization or deenergization of the electromagnet winding S. However, this turning movement of shaft it when in its depressed or right hand position is slight as compared to the turning movement permitted when in its normal position, and consequently the movement of the disc 35 for mechanically latching the shaft i2 is not suificient to change the circuit control set up on the contact fingers, but the turning of shaft l2 when not depressed does suificiently move the disc 35 to open certain circuits through the contact fingers and to close others.

In Fig. 2, the end portions only of the contact fingers are shown above the representation of the discs 35 and M, and likewise are represented as laid out or developed on a flat surface, although it is understood that these fingers are actually assembled in spaced parallel relationship around the outer surface of case Ill. The disc 35 operated by knob NB through shaft i2 is illustrated as provided with three contact sectors A, F, and J, the longer sector A cooperating with contact fingers B, C, D and E, the sector F cooperating with fingers G and H, and the sector J cooperating with fingers K and L.

With the disc 35 in its illustrated position, the sector A electrically connects fingers B and C only at their low resistance contact points, while sectors F and J do not engage low resistance points and consequently do not connect the two fingers respectively cooperating therewith. owever, when the shaft it or knob NB is pushed longitudinally to the right, finger Bis disengaged from finger C but finger C is connected to finger D at their outer contact points, and likewise fingers G and H are connected by sector F. When the knob NB is turned in a clockwise direction from its normal illustrated position, the disc 35 is moved downward longitudinally to disconnect finger B from finger C but to connect finger G to finger E, and likewise finger K is connected to finger L by sector J.

The center plunger XB is illustrated as con nected by shaft 28 to a development view of contact ring M which is movable only to the right as previously described. The contact ring M cooperates with fingers N, O, P and the fingers N and being electrically connected and fingers P and Q disconnected by ring M in its normal illustrated position, and when the plunger X3 is depressed, the contact ring M is moved to the right to disconnect fingers N and O and to con nect fingers P and Q.

In Fig. 3 of the accompanying drawings, a simplified circuit arrangement is shown as comprising one type of railway interlocking system in which the present controlling means may be employed. In this system the particular contact arrangement shown in Fig. 2 is employed, the contact fingers and movable contacts being represented in a very diagrammatic and conventional manner and cross referenced to the actual arrangement thereof shown in Fig. 2, it being understood of course that the particular contact arrangement is shown merely for illustrating its application to the particular system of Fig. 3, and that various other organizations and combinations of contact fingers and movable contacts may be provided to conform with the requirements of other circuits or of other types of systems.

A front view of a portion of the panel of Fig. l is shown in Fig. 3 having a simple track diagram suitably marked thereon corresponding to an actual track layout illustrated diagrammatically at the right of Fig. 3. This track layout comprises a straight stretch of track including a track switch TS power operated by a switch machine SM for allowing movements to and from a stretch of track diverging from this straight portion. Suitable east bound signals IAS, IBS and 508 have been illustrated diagrammatically as governing train movements in an east bound direction over the track switch TS, the high arm signal IAS being associated with high speed movements over the normal straight through route with switch TS in its normal position, the low arm signal IBS being associated with slower speed movements over the track switch TS in its reverse position, while ICS is a call-on signal for permitting movements into this portion of track when occupied by a train, such movements being for the purpose of switching or the like. Similar signals 2S and 3S are also illustrated for governing train movements in the west bound direction, the signal 2S being associated with straight through movements with switch TS in its normal position while signal its is associated with movements from the diverging track to the main track with switch TS in its reverse position.

A manual controlling means I is located on the track diagram of panel 5 at a point corresponding to the location of signals iAS, lBS and lCS along the actual track, this controlling means comprising an outer controlling button N'B which may be depressed or rotated and a concentric inner button X13 which may be depressed only, or in other words, this controlling device i is constructed as shown and described in connection with Fig. i and Fig. 2. Similar controlling devices 2 and 3 are likewise located on the diagram at points corresponding to the location of signals is and 3S respectively, but the outer buttons of these devices 2 and 3 need not be rotatable as will be later pointed out. In Fig. 3, the contacts have been shown in a very diagrammatic manner with dotted lines connecting the multiple contacting members with the manual means by which they are operated, the contacts, windings and armatures illustrated in Fig. 3 being given the same reference letters employed to designate the actual construction thereof shown in Fig. 2 and dis tinctive exponents have been assigned thereto corresponding to the particular controlling means i, 2 and 3.

Two stick neutral-polar relays NR and RR are shown at the controlling location which are distinctively energized according to the various combinations of operations of the manual controlling means I, 2 and 3. These NR and RR relays may be termed route relays, relay NR being associated with routes over the track switch TS in its normal position while relay RR is associated with routes over switch TS in its reverse position.

The condition of the route relays NR and RR is effective to control the track switch TS through the medium of a switch control relay WZ, and likewise to control the clearing of the signals through the usual signal control relays IGZ, ZGZ and 3GZ, the call-on signal ICS being under the control of relay ICZ as will be later described. A polar relay WP is indicated by dotted lines as repeating the position of track switch TS in the usual manner, or that is, relay WP is energized with one polarity when switch TS is in its normal locked position and with the reverse polarity when the switch is in its reverse locked position and is deenergized when the switch is unlocked or in operation. This WP relay may, for example, be controlled in the manner shown in Patent No. 1,517,236, granted to C. S. Bushnell, on November 25, 1924. The straight and the diverging portion of the illustrated track forms a single track section and is provided with a track circuit in the usual manner which has not been shown in detail, but it is to be understood that relay T is the usual normally energized track relay arranged to be deenergized by the entrance of a train into this track section.

In the circuit diagram of Fig. 3, the symbols and are employed to indicate the positive and negative terminals respectively of a suitable battery or other source of electrical energy, and the symbols (13+) and (B-) indicate opposite extreme positive and negative terminals respectively of a source of electrical energy having a center or intermediate tap designated by the symbols (CN) and the circuits with which the latter symbols are used may have current flowing in one direction or the other depending upon the particular terminal used in combination with the center tap (ON).

In describing the operation of the present system in Fig. 3, it will be clear that each of the controlling devices I, 2 and 3 comprise two manually operable buttons, the outer button NB being associated with the entrance end of a route and consequently may be termed the entrance button, while the inner button XB is associated with the exit end of a route and consequently may be termed the exit button. It will first be considered that the operator desires to establish an east-bound main line route, or a route from left to right on the straight portion of the track diagram, and consequently he first depresses the entrance button NB and next the exit button ){BZ When the entrance button N13 is depressed, the armature NS is moved into engagement with the magnet winding S and the movable contact F is moved downwardly to complete an energizing circuit for winding S which may be traced from contacts G and H connected by movable contact member F in its depressed or lower pos tion, through the winding S contacts 0 and N connected by movable contact member M in its upper position, wire 60, and through front contact 6| of track relay T, to The energization of winding S obviously retains the entrance button NB in its depressed position, and when the exit button X13 is pressed, an energizing circuit for relay NR is completed from through a resistance unit 63, contacts D and C connected by contacting member A in its lower position, through the windings of relay NR, back contact 64 of relay RR, contacts C and 13 connected by contacting member A in its upper position, contacts Q and P connected by contacting member M in its depressed or lower position to The operation of entrance button NB followed by the operation of exit button XB then energizes relay NR with current flowing from left to right through its windings, which, it will be considered, operates its polar contacts to their right hand position, and picks up its neutral armature. The exit button X8 however, is self-restoring so that the above pick up circuit for relay NR is only momentarily completed, and thereafter relay NR is held up over a stick circuit from through resistance unit 63, contacts D and 0 connected by contact member A in its lower position, through the windings of relay NR, back contact 64 of relay RR, polar contact 66 of relay NR in its right hand position, and through front contact 61, to

The polar switch control relay WZ is now energized over a circuit from (B+), through front contact 10 of relay NR, line wire ll, through the windings of relay WZ, to the center tap (ON). This energizing circuit positions the polar contact 12 of relay WZ to the right, which in the usual manner effects operation of the track switch by switch machine SM to its normal position over a control circuit which has been indicated by dotted line NC. When the track switch TS assumes its normal locked position, the switch repeating relay WP is energized to operate its polar contacts to the right and to pick up its neutral armature in the usual manner.

A circuit is then completed for energizing the signal controlling relay IGZ from through neutral front contact 15 of relay NR, polar con tact 16 of relay NR. in its right hand position, line wire 17, polar contact 18 in its right hand position and front contact 19 of relay WP, through the windings of relay lGZ, to The picking up of relay IGZ completes a circuit for clearing signal IAS from through front contact 86 of track relay T, back contact 8| of relay ICZ, front contact 82 of relay IGZ, polar contact 83 of relay WP in its right hand position, and to signal IAS as indicated by dotted line 84. The clearing of signal IAS then allows a train to traverse the route thus aligned, and as soon as such train passes signal IAS, the track relay T is dropped to open the energizing circuit for magnet winding S at contact 6|, thereby releasing the entrance button NB which returns to its normal outer position and opens the stick circuit for relay NR at contact D If the operator desires to establish this same route in the opposite direction, the entrance button NB is depressed first and then the exit button X13 is depressed, in which case the entrance button NB is retained in its depressed position by the attraction of armature N8 by the magnet winding S through contacts G and H ber F in its lower position, contacts 0 and N connected by member M in its upper position, wire 60, and through front contact SI of relay T, to The same route relay NR is then picked up upon the depression of button XB but with a different direction of current, the energizing circuit for relay NR now being from through a resistance unit 86, contacts D and C connected by A back contact connected by memthrough winding S energized over a circuit from )5 (ill 64 of relay RR, through the windings of relay NR, contacts C and B connected by A and through contacts Q and P connected by M to Relay NR is now held up after exit button XB is released over an obvious stick circuit completed by the operation of polar contact Eli to its left hand position connecting the left hand side of the winding of relay NR to in an obvious manner. The energization of the normal route of relay NR of course calls for a normal position of track switch TS the same as before, and consequently the switch control relay W Z and relay WP remain in the same energized position. However, the left hand position of the polar contacts of relay NR now picks up relay ZGZ over a circuit from through neutral front contact l5 and polar contact 16 in its left hand position of relay NR, line wire 88, polar contact 89 in its right hand position and neutral front contact 90 of relay WP, and through the windings of relay ZGZ, to

The west bound signal 2S is then cleared over a circuit indicated as including front contact 92 of track relay T and front contact 93 of relay ZGZ, thereby allowing a train to traverse the route thus aligned. In a similar manner, the entrance button NB is released when a train passes signal to drop track relay T and deenergize magnet winding S at contact 6|, thereby releasing the retaining armature N8 and the release of the entrance button NB opens the stick circuit for relay NR at contact D Now considering that the operator desires to align an east bound diverging route over track switch TS, it will be clear that entrance button N18 is first pressed and then exit button X13 is pressed. The entrance button NB is then retained by the energization of winding S over the same circuit as previously described, and when the exit button X3 is pressed a pick up circuit is completed for the reverse route relay RR from through resistance unit 63, contacts 1) and C connected by A back contact 95 of relay NR, through the windings of relay RR, contacts C and B connected by A and contacts Q and P connected by M to Relay RR is thus energized by current flowing from left to right through its windings which operates its polar contacts to the right to complete an obvious stick circuit connecting the right hand side of its windings to through its polar contact 96 in its right hand position and through its neutral front contact 97, thereby retaining relay RR energized after the exit button XB is released.

The picking up of the reverse route relay RR energizes the switch controlling relay WZ with a reverse direction of current flowing from the center terminal (CN), through the windings of relay WZ, line wire H, and through front contact 99 of relay RR, to (B). Contact E2 of relay WZ is then operated to its left hand position to effect operation of the track switch TS to its reverse position by operating switch machine SM over a reverse control circuit indicated by dotted line RC. When the track switch TS is in its reverse locked position, relay WP is energized with a reverse direction of current to pick up its neutral armature and operate its polar contacts to their left hand position.

The signal control relay M712 is now energized from through neutral front contact llll and polar contact N2 of relay RR in its right hand position, line wire Hi3, polar contact l3 in its left hand position and neutral front contact 19 of relay WP, through the windings of relay IGZ, to

() The picking up of relay IGZ with the polar contacts of relay WP in their left hand position clears signal lBS over a circuit including front contact 80 of relay T, back contact 8! of relay lCZ, front contact 82 of relay lGZ, polar contact 83 of relay WP in its left hand position, and to signal lBS as indicated by dotted line N15.

The clearing of signal IBS allows a train to traverse this diverging route over track switch TS in its reverse position, and as soon as such a train passes the signal IBS, the entrance button NB is released the same as before by deenergizing winding S at front contact 6| of relay T, which in turn deenergizes relay RR at contact D However, if it is desired to align this diverging route in the opposite or west bound direction, the entrance button NB is first pressed and then exit button XB is pressed. The entrance button N13 is retained in its depressed position by the attraction of its armature NS due to the energization of winding S over a circuit which will now be obvious from the previous descriptions of the energizing circuits of winding S and S Relay RR is then energized with a reverse direction of current upon the depression of exit button XB over a circuit from through a resistance unit lll l, contacts D and 0 connected by A through the windings of relay RR, back contact 95 of relay NR, through contacts 0 and B connected by A and through contacts Q and P connected by M to Relay RR is retained energized after the exit button X3 is released by a stick circuit connecting the left hand side of its windings to through its polar contact 98 in its left hand position and through its neutral front contact 91.

The energization of relay RR again calls for the reverse position of track switch TS and consequently relay WP remains energized with a polarity operating its polar contacts to their left hand position. However, the relay RR is now energized with a reverse direction of current operating its polar contact to their left hand position, which completes a circuit energizing signal control relay ZGZ from neutral front contact NH and polar contact I62 of relay RR in its right hand position, line wire Hi6, polar contact I01 in its left hand position and neutral front contact I08 of relay WP, and through the windings of relay 3GZ, to

The picking up of relay 3GZ clears signal 3S over a circuit including front contact 92 of track relay T and front contact H19 of relay 3G2. The clearing of signal 3S allows a train movement in a west direction over track switch TS in its reverse position, and such a train movement releases the entrance button NB by deenergizing its retaining winding S at open front contact Bl of track relay T, which in turn opens the stick circuit for relay RR at contact D In this manner it may be seen that the controlling devices I, 2 and 3 can be operated or depressed in various combinations to align any desired normal route in the present embodiment. However, as previously stated, it is sometimes desirable to establish a route for abnormal train movements or, for example, to allow a train to enter a route already occupied by another train by the use of a call-on signal. In the present disclosure, only one of the controlling means, or control button I is employed to provide a call-on signal, but it will be clear that the other buttons 2 and 3 could be similarly arranged if desired.

The entrance button NB in Fig. 3 is rotatable in a clockwise direction when in its outer position as previously described in connection with Fig. 1

and Fig. 2, and consequently when the operator desires to provide a call-on signal indication or to clear signal ICS, the entrance button NB is turned in a clockwise direction and either exit button X3 or exit button X5 is pressed to allow such a train movement either on the normal or diverging routes. It will be noticed in Fig. 3 that is connected to contact E as well as contact D and it is considered that the movable contact A is operated to the left by rotation of button NB which connects contact E with contact C so that is connected to contact C when the button NB is turned the same as when it is depressed.

It will then be clear that the turning of the entrance button NB allows the selective energization of either route relay NR or RR according to the subsequent pressing of either exit button KB or XB in the same manner as when the entrance button N13 is depressed. Consequently in aligning a call-on signal route for allowing an east bound train movement, the signal control relay IGZ will be energized in the same manner as in aligning a route for a normal east bound train movement. However, a movable contact J is operated to the left by rotation of the entrance button NB to connect con tacts K and L thereby energizing the call-on signal control relay IGZ over an obvious circuit including line wire H0. The energization of relay ICZ clears the call-on signal ICS as indi cated by the circuit from through front contact III of relay ICZ, front contact H2 of relay IGZ, and to the signal ICS as indicated by dotted line H3.

It will be clear that the picking up of the call-on control relay IGZ permits the call-on signal to be given when a train occupies a particular route as such signal control does not include a front contact of track relay T as do the control circuits for signals governing the higher speed train movements. It will also be clear that the picking up of the call-on signal controlling relay ICZ prevents clearing of the other east bound signals IAS and IE8 as their controlling circuits include back contact 8| of relay ICZ.

It will now be clear from the foregoing description of the operation of the present system shown in Fig. 3 that the present controlling means permits the operator to establish various normal routes in a railway interlocking system by merely defining the two ends thereof, or by manually pressing the proper entrance and exit buttons, the route thus manually established being retained by magnetically sticking the entrance button in its depressed position until a train moves over the established route to deenergize the magnetic sticking means and release the entrance button which restores the system to a normal condition. In this manner, the operator is relieved of the otherwise necessary operation of operating the entrance button back to its normal position to restore such normal condition, and consequently he may direct his attention to subsequent train movements, or in other words the operator in such an arrangement is only concerned with establishing routes which he can start as soon as the train traversing the previously established route has departed from the track section controlling the releasing of the entrance button next to be operated.

It is believed, however, that the establishing of routes in the above system may be further expedited by providing means permitting the operator to start the alignment of a route by operating the entrance button at any time after the train enters the previously established route and before such train has fully traversed this previously established route. The above operation may be provided by modifying the system shown in Fig. 3 in the manner shown in Fig. 4, which modification may be briefly described as providing a means for controlling the energizing circuits for the retaining magnet windings S S and 5 whereby these energizing stick circuits are only momentarily opened when a train enters the associated track section to drop track relay T, thus releasing the retaining armatures NS N8 and N3 but permitting reenergization of the windings S S and S by pressing the associated entrance button even while the track relay T is still dropped.

More specifically, it may be seen in Fig. 4 that the same track relay T is shown as in Fig. 3 which controls the energization of the windings S S and S over the wire BI] and through its front contact 6| in the same manner. However, in Fig. 4, a slow releasing track repeating relay TP is provided and normally energized through front contact I20 of relay T, and a back contact I21 of relay TP is provided in multiple with front contact SI of relay T.

In such an arrangement, a train upon entering an aligned route drops relay '1 and before the slow repeating relay TP drops, the stick ener gizing circuits for magnet windings S are open at front contact 6| the same as described in Fig. 3 to release the retaining armatures NS. However, the subsequent dropping of relay TP shunts around the open front contact 6| thus permitting any of the windings S to be immediately energized by pressing the associated entrance button N13 to close its circuit through stick contacts G, H and F although a train may still be shunting relay T.

In other words, the arrangement in Fig. 4 momentarily opens the stick circuit for windings F only when a train enters a route but does not likewise open the circuit when the train departs from this route as front contact 6| of relay T will then have closed before back contact IE! of relay TP opens.

It is also contemplated that an operator may for some reason desire to manually cancel an aligned route, or that is, to release an entrance button NB to change a route or the like before it is accepted by a train. Consequently in Fig. 3, the energizing circuit for each of the windings S which retains the associated entrance button NB has been shown as including normally closed contacts O, N and M of the exit button concentric therewith, whereby it will be clear that the depression of the exit button which is physically associated with the depressed entrance button will immediately release such entrance button by opening its energizing stick circuit at contacts O--N-M.

It will of course be clear that the entrance button and the exit button concentric therewith are never both depressed in the process of aligning a route, and consequently such an arrangement provides a convenient method of releasing a depressed entrance button in the event the operator desires to change a route or the like. However, the above cancelling means is merely a refinement in the system, as it was previously stated that the entrance button NB could be forcefully restored from its depressed position by pulling outwardly, and consequently in some cases the contacts 0, N and M could be omitted from the energizing circuits of the associated windings S.

It is some times desirable to retain an established route after a train has passed thereover, such as to permit a second train to traverse the same route for example. Consequently the entrance buttons NB have been so arranged that if the operator desired to prevent the automatic releasing thereof, he merely turns the knob NB slightly after it has been depressed, thus mechanically retaining such a depressed position thereof until he manually restores a normal condition by turning in the opposite direction. This turning movement for mechanically locking the button NB in its depressed position, however, does not move the contacts such as A and J in Fig. 3 sufficiently to the left to close the circuits which are closed thereby when the button NB is turned to provide a call-on signal indication as previously described.

In describing the operation of the present manual controlling means, attention has been directed only to the specific system shown in Fig. 3, but it is to be understood that the particular arrangement shown in Fig. 3 has been employed merely to illustrate one manner in which the present controlling means may be employed in an interlocking system. The specific circuit means for executing the conditions established by the manual controlling means, such as the means for effecting the control of the track switch and the control of the signals according to the established energization of the route relays, has not been shown in detail as there are many well known methods of accomplishing such control. The wayside signal clearing circuits and the switch operating circuits, for example, have merely been indicated by dotted lines connecting these devices with the relay contacts which are directly involved in the present description of the operation, but it is to be understood that these circuits will in practice be also controlled by other devices such as lock relays, track relays of adjacent track sections and the like, all in accordance with well recognized principles of railway signalling.

In other words, the above rather specific description of one form of the present invention is given solely by the way of example, and is not intended in any manner whatsoever in a limiting sense. It is also to be understood that various modifications, adaptations and alterations may be applied to the specific form of the controlling means shown in Fig. 1 and Fig. 2 in order to meet the requirements of practice, without in any manner departing from the spirit or scope of the present invention, except as limited by the appended claims.

What I claim is:-

1. In an interlocking system for railroads, a track layout and a miniature track diagram corresponding thereto, a plurality of manually operable controlling means on the track diagram each comprising an outer circuit-controlling button and a concentric inner circuit-controlling button, means for establishing routes over the track layout by operation of the controlling means, and magnetic means controlled by traffic over said routes for retaining each outer circuitcontrolling button in its operated position.

2. In an interlocking system for railroads, a track layout having switches and signals and a miniature track diagram corresponding thereto, a plurality of manually operable controlling means on the track diagram for each of said signals and each comprising a depressible outer circuit-controlling button and a concentric depressible inner circuit-controlling button, means for establishing each route over the track layout by depressing the outer circuit controlling button for the entrance to such route and the inner circuitcontrolling button for the exit of such route, magnetic means controlled by traffic over each of said routes for retaining the outer circuit-controlling button for the entrance to that route in its depressed position until a train passes into such route, and manually selective mechanical means for retaining each outer circuit controlling button in its depressed position until manually restored irrespective of said magnetic means.

3. In a traffic controlling system for railroads, manually operable means comprising an outer control button and an inner concentric control button, electromagnetic means for retaining the outer control button in its operated position, and an energizing circuit for the electromagnetic means including contacts closed by the outer control button in. its operated position and contacts closed by the inner control button in its normal position.

4. In a traffic controlling system for railroads, manually operable means comprising an outer control button and an inner concentric control button, electromagnetic means for retaining the outer control button in its operated position, and circuit means controlled by train movements for causing the electromagnetic means to release the outer control button.

5. In a. traific controlling system for railroads, manual controlling means comp-rising an outer control button and an inner control button, electrom-agnetic means for retaining the outer control button in its operated position, an energizing circuit for the electromagnetic means including contacts closed by the outer control button. in its operated position, tramc controlling devices controlled by operation of the outer and inner control buttons, and means for momentarily opening the energizing circuit for the electromagnetic means by a train movement governed by said trafiic controlling devices.

6. In a traffic controlling system for railroads, manual controlling means, electromagnetic means for retaining the manual controlling means in its operated position, an energizing circuit for the electromagnetic means including contacts closed by the manual controlling means in its operated position, traffic controlling devices controlled by operation of the manual controlling means, and means for momentarily opening the energizing circuit for the electromagnetic means by a train movement governed by said tr'affic controlling devices.

7. In an interlocking system for railroads, a track layout having a plurality of different routes, a plurality of signals for governing trafiic through the track layout over the different routes in opposite directions, a miniature track diagram corresponding to the track layout, manually operable self-restoring entrance buttons located on the track diagram at points corresponding to each of said signals, a manually operable selfrestoring exit button arranged within. each en-- trance route button, a polar route re.ay corresponding to each route over the track layout, means for energizing each route relay with one direction of current or with another direction of current in accordance with the joint operation of the entrance button at one end of the route and the exit button at the opposite end of the route with the direction of current flow determined by the end at which the entrance button is operated, electro-magnetic means retaining each entrance route button in its operated position, stick circuit means for maintaining each route relay energized while the associated entrance route button is in its operated position, means con trolled by each route relay for aligning its route over the track layout and clearing the signal for such route at the end corresponding to the operated entrance button, and means for releasing each entrance button from its operated position when a train enters an associated route over which the associated signal governs traffic, whereby a signal is maintained cleared until a route is accepted by a train. and is then automatically put to stop.

8. In an interlocking system for railroads, a track layout having a plurality of different routes, a plurality of signals for governing traflic through the track layout, a miniature track diagram corresponding to the track layout, selfrestoring entrance route buttons on the track diagram at points corresponding to the location of the signals, a self-restoring exit button concentrically arranged within each entrance route button, means for establishing each route of the track layout and clearing the signal governing traflic over such route by depressing the entrance route button at the entrance end and the exit route button at the exit end of such route, said route establishing means remaining effective so long as the entrance button governing that route remains in a depressed position, and electromagnetic means for each entrance button efiective to maintain such entrance button in its depressed position until a train enters the route established thereby.

9. In an interlocking system for railroads, a track layout having a plurality of different routes, a plurality of signals for governing trafficthrough the track layout, a miniature track diagram. corresponding to the track layout, entrance route buttons on the track diagram at points corresponding to the location of the signals, an exit route button concentrically arranged within each entrance route button, means for establishing each route and clearing a norm-a1 signal governing train movements over that route of the track layout by depressing the entrance route button at the entrance end and the exit route button at the exit end of such route, means for establishing each route and clearing a call-on sign-a1 governing train movements over that route of the track layout by turning the entrance button at the entrance end and pressing the exit button at the exit end of such route, and electromagnetic means for retaining each entrance button in its depressed position until a train enters the route established thereby, whereby a normal signal is automatically put to stop but a call-on signal is manually put to stop.

10. In an interlocking system for railroads, a track layout capable of forming a plurality of routes, signals for governing trafiic over said routes, self-restoring manually operable control means associated with the ends of said routes, route control means responsive to the joint operation of said manually operable control means for only the opposite ends of a particular route effective to set up that route and to clear its signal, stick circuit means for maintaining said route control means effective irrespective of the self-restoration of said manually operable control means, and traflic controlled means acting to release said stick circuit means only momentarily upon the entrance of a train into an estab lished route, whereby the route control means for the same route may be rendered effective for a second train while the route is still occupied by the first train.

11. In an interlocking system for railroads, a track layout having a plurality of routes and including at least one track switch, signals for governing traffic in opposite directions through said routes, a miniature track diagram corresponding to said track layout, a self-restoring control button on said track diagram for each of said signals and in corresponding positions, clectro-responsive means controlled by the joint operation of only said control buttons at the opposite ends of any route through said track lay-- out for automatically controlling the track switch to a proper normal or reverse position to establish that particular route and to clear the signal for such route, a track relay associated with each of said routes, contacting means controlled by said track. relay and operating to close a contact shortly after deenergization of said track relay and to open said contact shortly after energization of said track relay, and stick circuit means for said electro-responsive means including a front contact of said track relay in multiple with said contact of said contacting means.

12. In an interlocking system for railroads, a track layout having a track switch to thereby form a plurality of routes, signals for governing traiiic in opposite directions through said routes, a miniature track diagram corresponding to said track layout, a self-restoring control button on said track diagram for each of said signals and in corresponding positions, a track relay, a normally energized track repeating relay, electroresponsive means controlled by the joint operation of only the control buttons at the opposite ends of any particular route through said track layout for automatically controlling the track switch to a proper normal or reverse position to establish that route and to clear the signal for such route, and stick circuit means for maintaining said electro-responsive means effective, said stick circuit means including a front con tact of said track relay connected in multiple with a back contact of said track repeating relay.

13. In a switch and signal system; a track layout including a plurality of different routes between signals for governing traflic in opposite directions over such routes with at least one of such signals including a main signal and a call on signal; a miniature track diagram corresponding to said track layout; an entrance button and an exit button on the track diagram for each of said signals, said entrance and exit buttons being of the self-restoring biased to normal type when depressed, and said entrance buttons being of the stay-where-put type when rotated; route establishing means associated with each route, said route establishing means for a particular route being responsive to the depression of the entrance button for the entrance point to that route and the depression of the exit button for the exit point to that route to establish such route and clear the main signal therefor, and also being responsive to the rotation of said entrance button and the depression of said exit button to establish such route and clear the call-on signal therefor, said route establishing means remaining effective so long as the entrance button is maintained in its depressed or rotated position; and electro-magnetic means for each entrance button for maintaining such button in its depressed position until a train enters the route which said entrance button is then governing; whereby said main signal is automatically put to stop by the passage of a train, and whereby a call-on signal is maintained clear until the governing entrance button is manually restored to its normal position.

14. In a switch and signal control system for railroads; a track layout including a plurality of difierent routes between signals for governing trafiic in opposite directions over such routes; a control panel including a miniature track diagram corresponding to said track layout; an entrance button on said track diagram for each of said signals, each of said entrance buttons having one operating position in which it is biased to return from such operating position to normal and also having a locked operating position in which it remains until manually restored to normal; an exit button associated with each of said entrance buttons, each of said exit buttons being biased so as to be self-restoring from its operating position to its normal position; route establishing means associated with each route,

. said route establishing means for a particular route being responsive to the actuation of an entrance button for the entrance point to that route to either of its operated positions and to the operation of the exit button for the exit point to that route to establish such route and clear a signal therefor; and electro-magnetic means associated with each entrance button and effective to maintain such entrance button in its said one operated position until a train enters the route which such entrance button is then governing; whereby a route may be set up by an entrance-exit manipulation in a manner to be automatically self-restoring or to require manual restoration as desired by an operator.

15. In an interlocking system for railroads; a track layout having a plurality of diiferent routes each of which includes at least one track switch; signals for governing traffic over each of said routes; a control panel including a miniature track diagram corresponding to said track layout; an entrance button located on said control panel for each entrance point for said routes, each of said entrance buttons being biased from its operated position toward its normal position;

an exit button located on said control panel for each exit point for said routes, each of such exit buttons being biased from its operated position to its normal position; route establishing means associated with each route and responsive to the joint operation of an entrance button for the entrance point of such route and the exit button for the exit point of that route to operate the track switch for such route and to clear a signal therefor; electro-magnetic means associated with each entrance button and effective when energized to maintain such entrance button in its operated position; and circuit means for energizing each electro-magnetic means when its associated entrance button has been operated, said circuit means including a front contact of track relay of the route which such entrance button is then governing, whereby such entrance button is released so as to be restored to its normal position upon such route becoming occupied by a train.

16. In a switch and signal control system for railroads; a track layout including a plurality of difierent routes between signals for opposite directions of traflic, each of such routes including at least one track switch; an entrance button and an exit button for each of said signals both of such buttons for each signal being of the biased to normal type; electro-magnetic means associated with each entrance button efiective when energized for maintaining its associated entrance button in an operated position; route establishing means responsive to the operation of an entrance button at one end of a route and the exit button at the opposite end of such route to set up that route by operating the track switch and clearing the signal at the end corresponding to the operated entrance button; and stick-circuit means for energizing said electro-magnetic means of the operated entrance button dependent upon the unoccupied condition of the route which such operated entrance button is then governing, said stick circuit means for each entrance button including a normal contact of the associated exit button; whereby an established route may be returned to stop by the operation of the exit button at the entrance end of such route.

WIN'I'HROP K. HOWE. 

